A social identity perspective on interoperability in the emergency services: Emergency responders' experiences of multiagency working during the COVID‐19 response in the UK

Abstract Recent research has shown that multiagency emergency response is beset by a range of challenges, calling for a greater understanding of the way in which these teams work together to improve future multiagency working. Social psychological research shows that a shared identity within a group can improve the way in which that group works together and can facilitate effective outcomes. In the present study, 52 semistructured interviews were conducted with 17 strategic and/or tactical responders during the COVID‐19 pandemic to understand the possible role of shared identity in the multiagency response to COVID‐19 and whether this was linked to factors that facilitated or challenged interoperability. Findings show evidence of a shared identity at a horizontal intergroup level among responders locally. However, there was limited evidence for a shared identity at the vertical intergroup level between local and national responders. Three key factors linked to shared identity appeared to contribute to effective multiagency working. First, pre‐existing relationships with other responders facilitated the ease with which responders were able to work together initially. Second, a sense of ‘common fate’ helped bring responders together, and finally, group leaders were able to strategically reinforce a sense of shared identity within the group.

As defined in the Joint Emergency Services Interoperability Principles (JESIP), interoperability is 'the extent to which organizations can work together coherently as a matter of routine' (JESIP, 2013, p. 2).
However, interoperability has been consistently highlighted as a key challenge that hinders effective joint working. Indeed, in a review of 32 major incidents between 1986 and 2010, coordination between responding agencies was identified as a persistent challenge (Pollock, 2013). To address this, JESIP was introduced to improve interoperability by providing five principles for joint working: colocate, communicate, coordinate, jointly understand risk and shared situational awareness (JESIP, 2021, Table 1).
Yet, even with the introduction of JESIP, interoperability has continued to be highlighted as a challenging issue in emergency response. For example, Part 2 of the Manchester Arena Inquiry found 'significant failures in relation to each of [the JESIP] principles for joint working on the night of the Attack' (Manchester Arena Inquiry Volume 2-I, 2022, p. 45). For example, communication challenges between the emergency services led to significant delays in the FRS arriving at the scene (see also Kerslake, 2018). However, these are not just UK-based challenges. Similar challenges have been highlighted in emergency response internationally, not only in Europe (e.g., Sweden: Palm & Ramsell, 2007;Wimelius & Engberg, 2014; and the Netherlands: Bharosa et al., 2009), but also across the globe (e.g., the United States: Majchrzak et al., 2007;National Commission on Terrorist Attacks Upon the United States, 2004; Indonesia: Rencoret et al., 2010 andHaiti: Patrick, 2011). This suggests that lessons identified in previous reports are not being learned (cf. Pollock, 2017Pollock, , 2021 and highlights the need for a better appreciation of the persistence and intractability of interoperability challenges. Interoperability has also been foregrounded by the COVID-19 pandemic. The pandemic has required a multiagency response both at the vertical level, involving interactions between local and national groups (e.g., between local multiagency groups and government agencies), but also at the horizontal level, involving interactions between groups locally (e.g., between different emergency service organizations). Accordingly, in 2020, multiagency coordination groups were established across the UK to bring together local responders from organizations including the emergency services, local authorities, and other key organizations to provide a joined-up response to  In the present research, we zero in on the multiagency response to COVID-19 to try to better understand the factors that might facilitate or challenge interoperability. For this purpose, we carried out a series of semistructured interviews with Police, FRS and Ambulance responders from across the UK who were involved in the COVID-19 response at a strategic and/or tactical level. Specifically, we sought to address a gap in current research by exploring the role of shared identity in multiagency working in this context: was this relevant, how did it arise and how did it function? However, before describing this research, we first seek to better understand the context in which multiagency working operates by summarizing research on multiteam systems (MTSs), before introducing the Social Identity Approach and its relevance to this research.

| Multiteam systems
MTSs are comprised of at least two teams that work directly and interdependently to achieve a collective goal (Mathieu et al., 2001;Shuffler et al., 2015). They centre on the dynamics of subteams nested within a superordinate team. Each team within an MTS possesses specialist skills and may have different individual goals that contribute to the same collective goal (Davison et al., 2012).
In contrast to traditional teams, MTSs require team members to coordinate effectively both within their individual subteam, as well as across the teams that form the superordinate MTS. For example, in multiagency emergency response, the usually separate organizations of the Police, FRS and Ambulance Services form subteams that are nested within the superordinate team of the emergency services.
Each of these teams has different subgoals-for example, neutralizing a threat (Police), stabilizing the structure of a building (FRS) and treating casualties (Ambulance)-which all contribute to the collective superordinate goal of saving lives and reducing harm.
T A B L E 1 The five principles for joint working (JESIP, 2021) Principle Description

Colocate
Colocate with commanders as soon as practicably possible at a single, safe and easily identified location near the scene.

Communicate
Communicate using language which is clear and free from technical jargon and abbreviations Coordinate Coordinate by agreeing on the lead service. Identify priorities, resources, capabilities and limitations for an effective response, including the timing of further meetings.
Jointly understand risk Jointly understand risk by sharing information about the likelihood and potential impact of threats and hazards, to agree on appropriate control measures.
Shared Situational Awareness Shared Situational Awareness was established by using METHANE-an established reporting framework that provides a common structure for responders and their control rooms to share incident information (see JESIP, 2021, p. 16)and the joint decision model-a model used to bring together available information, reconcile potentially differing priorities and then make effective decisions together (see JESIP, 2021, p. 19).
MTS research has been applied to high-risk and dynamic settings such as military operations (e.g., DeCostanza et al., 2014;Liu et al., 2003) and medical emergencies (e.g., Mathieu et al., 2001). More recently, this theoretical perspective has been applied to emergency response (e.g., Brown et al., 2021;Waring et al., 2020). To this end, Waring et al. (2020)  As a theoretical framework to guide this exploration, social identity theorizing has been used to help researchers and practitioners understand how groups operate in MTSs. For example, MTSs whose subgroups share a superordinate identity have been found to collaborate more effectively (Mell et al., 2020

| The Social Identity Approach
The Social Identity Approach is a social psychological framework that seeks to understand the distinct contribution that group life makes to people's psychology and behaviour. The approach is comprised of two interrelated theories-social identity theory (Tajfel & Turner, 1979) and self-categorization theory (Turner et al., 1987)-that are built upon a foundational insight that as well as defining themselves, and behaving, in terms of their personal identity as individuals (Turner, 1982), people can, and often do, also define themselves and behave, in terms of their social identity as members of social groups (Tajfel & Turner, 1979). So, whereas personal identity defines a sense of 'I' and 'me' that describes a person in contrast to others, social identity defines the self in terms of 'we' and 'us' in ways that psychologically connect people to other members of their in-group.
There are several factors that facilitate the development of a shared identity between individuals, including a shared sense of common fate (i.e., the feeling that 'we're all in this together'; Brewer, 2000;Drury, 2018), and effective identity leadership (i.e., helping group members see themselves as 'we' as opposed to 'I' ;Steffens et al., 2014). Importantly, in a range of social and organizational contexts, this sense of social identity is observed to be the primary driver of people's behaviour primarily because, as Turner (1982, p. 21) argues, it is what 'makes group behaviour possible' (cf. Haslam et al., 2003). In particular, a shared identity within a group is a basis for coordination and cooperation between group members because it increases their psychological sense of interconnection and common purpose (Haslam et al., , 2009). At the same time, social identity provides group members with a basis for developing a shared understanding of situations, as well as common norms for behaving in those situations (Reicher et al., 2010). Consequently, these shared definitions and common norms can improve group behaviour in those who perceive themselves to share social identity (i.e., who are bound together by a common sense of 'us'; Drury et al., 2009;Haslam et al., 2009) while also fostering trust and respect among group members (Haslam et al., 2012;Turner et al., 1987).
Demonstrating these positive effects, Haslam et al. (2009) showed that individuals who had high group identification were more willing to display organization citizenship than those with lower levels of identification. More generally, a large body of research demonstrates that when group members perceive themselves to share a social identity, this increases their motivation to contribute to the group's success, as well as their ability to do so (as reviewed by Ellemers et al., 2004;Haslam, 2004).
At the same time though, people also have multiple social identities which can become salient in different contexts (e.g., us women, us Londoners, us paramedics; Millward & Haslam, 2013;Turner et al., 1987). According to the self-categorization theory, these can also be defined at multiple levels of abstraction (Turner, 1985). For example, a paramedic, Anne, can define herself, as a member of a particular team, as a member of a particular profession, or as an emergency worker (see Figure 1). It follows too that this is DAVIDSON ET AL.
| 3 likely to have a significant bearing on her behaviour. For example, when (and to the extent that) she defines herself as a member of a particular team, Anne should be motivated to advance the interests of that team; but when (and to the extent that) she defines herself as an emergency worker, Anne should be motivated to advance the interests of emergency workers.
But, when do these identities become salient in a given context? When might Anne identify as a paramedic rather than an emergency worker? In this regard, the self-categorization principles of fit and perceiver readiness allow us to understand which of many identities might become salient, and therefore guide perception and behaviour, in a given context (Oakes, 1987; see Turner & Reynolds, 2012, for an overview). First, we would expect an in-group category to become salient when a person perceives the differences between themselves and fellow ingroup members to be smaller than those between in-group and out-group members (also known as comparative fit; Haslam, 2004). For example, if Anne (a paramedic) was surrounded by paramedics and police officers, we would expect her identity as a paramedic to be salient. At the same time though, the nature of these differences must be consistent with Anne's expectations about the groups (also known as normative fit; Haslam, 2004 Importantly too, the principles of fit work in interaction with perceiver readiness (or accessibility, Oakes et al., 1994;Turner et al., 1994). This refers to the ways in which our willingness to take on a given social identity is determined by such things as our personal history and our strength of prior identification (Haslam, 2004). For example, if Anne has worked as a paramedic for a long time, and has a strong commitment to her job, but has limited experience working as part of a team with police officers and firefighters, she may be more likely to identify as a paramedic than an emergency worker.
In line with this understanding that people can have multiple identities, it is beneficial to understand which of these identities is most likely to be important in a particular context. For example, is Anne's commitment to the emergency services, and thus her ability to work in a group with police officers and firefighters, likely to be greater if her subgroup identity of being a paramedic is denied?
To address this question, Mühlemann et al. (2022) recently proposed the Social Identity Model of Organizational Change (SIMOC).
This suggests that employees will identify with the newly emerging organization and adjust to organizational change more successfully if they are able to maintain their pre-existing identity. On the other hand, when pre-existing identities could not be maintained, adjustment to organizational change was determined by the extent to which employee supervisors helped to create and promote a new, positive, and meaningful organizational identity (Mühlemann et al., 2022). Thus, the development of a successful group identity following two groups merging is facilitated when subgroup identities are not denied, but instead, individuals are able to hold onto their subgroup identities. With this in mind, it could be argued that Anne's commitment to being an emergency worker will be greater when her subgroup identity as a paramedic is maintained within the superordinate identity. Alternatively, the newly formed groups will require a leader who helps to create and promote a positive and meaningful identity for the group (see also Haslam et al., 2021;Hogg, 2001;van Knippenberg & Hogg, 2003 With this in mind, we conducted regular, semistructured interviews with responders involved in the COVID-19 response at a strategic and/ or tactical level from across the UK. The purpose of this was to understand the possible role of shared identity in the multiagency response during the initial months of the pandemic in 2020. More specifically, the aims of this research were to address the following research questions (RQs): RQ1. Was there any evidence of a shared identity between responders?
RQ2. What factors facilitated or challenged effective multiagency working?
RQ3. If there was a sense of shared identity, was this linked with any of the factors that facilitated or challenged effective multiagency working?

| The emergency response context in the UK
Within the UK, the multiagency response to major incidents and emergencies is managed through a three-tiered command structure: strategic, tactical and operational (as set out in the Civil Contingencies Act, CCA, 2004; see Table 2). This structure is comparable to that in other countries which also adopt a three-tiered command structure for emergency management. For example, Belgium uses a similarly structured strategic-tactical-operational command system, and Sweden's command is separated into a system-operational-task commands (Bram et al., 2016).
This tiered structure brings together partners from two categories: Category 1 (e.g., the emergency services, local authori-

| Procedure
Fifty-two semistructured interviews were conducted with 17 responders from Police (N = 8), FRS (N = 7) and Ambulance Services (N = 2) across the UK who were involved in the COVID-19 response at a strategic and/or tactical level-all responders were involved in the SCG and/or TCG within their local area (see Table 3, for a full list of participant details). Repeated interviews took place between April 13th, 2020 and July 27th, 2020. Potential T A B L E 2 Tiers of command and associated responsibilities emergency responders adopt when responding to incidents (JESIP, 2021) response, responders took part in an unequal number of interviews, ranging between 1 and 12 each (M = 4, SD = 3.15).
To ensure anonymity, responders were given a unique participant number (1-17; see Table 3).
Interviews took place either over the telephone or via the online platform, Microsoft Teams, and were recorded with a dictaphone.
Before their first interview, responders were provided with an information sheet electronically. A verbal consent protocol was read out to responders before their first interview, and they were asked to verbally consent to take part.
The interviewer followed an interview schedule during the interview which was developed following discussions between members of the research team. For the first interview, questions focussed around roles and responsibilities (e.g., 'What is your current role within the COVID-19 response?'); multiagency working (e.g., 'Can you tell me about the range of partners that you are involved with in this response?'); strengths and weaknesses (e.g.,

'
Can you tell me about any challenges you have faced?'); adaptation (e.g., 'Are there any specific areas of improvement that you have recognized in this response?'); and training and guidance (e.g., 'Is there any specific training or guidance you are following in your response?'). Subsequent interviews focussed on any changes or developments in the response since the previous interview.
Specific questions relating to social identity were not asked; this allowed responders to discuss matters that were important to them and allowed any reference to social identity to occur spontaneously without direct prompting from the researcher.
The full interview schedules can be found in Supporting Informa-

| Research context
The role of the SCG in the COVID-19 response was to take overall responsibility for the response and to establish the strategic framework within which the tactical and operational levels of command could operate. On the other hand, the role of the TCG was to provide a coordinated tactical response to COVID-19. For example, responders discussed that their role included supporting personal protective equipment deliveries, setting up temporary mortuaries, and ensuring the vulnerable population was adequately cared for. In addition, in most of the areas interviewed the Police chaired the SCG and/or TCG. In one area the FRS chaired the SCG.
When Police or FRS was not chair, these meetings were chaired by a representative from the health sector.
A summary of key dates, events, and considerations that their SCG and/or TCG needed to discuss to facilitate the operational response during this period and events provided by participants during the interviews is presented in Table 4.

| Data analysis
Interviews were analysed using thematic analysis-a method for identifying, analysing and reporting themes (patterns) in data (Braun & Clarke, 2006). A semideductive approach was utilized-while there were no predetermined themes, the Social Identity Approach provided researchers with a general sense of reference when formulating the RQs and conducting the analysis (e.g., use of 'us vs. them' language).
Data familiarization involved the lead author listening to the recordings of all interviews and then transcribing sections of interviews relevant to the multiagency response to COVID-19. Sections of the interviews where responders discussed other response activities that were not specific to the multiagency response to COVID-19 (e.g., the Black Lives Matter protests during the Summer of 2020) were not included in the transcription. The lead author then read and reread the transcripts to identify sections that were relevant to the three RQs-for example, any evidence that social identity processes might be present, or any factors that might be facilitating interoperability. From this, initial codes were generated for these sections (e.g., 'communication outside of the local area'; 'the importance of understanding the purpose of the response groups'). These codes were then reviewed, and potential themes were identified by the researchers (e.g., 'crossarea relationships' and 'understanding the roles of partners'). Once themes had been identified, these were reviewed, defined and named by the researchers. Following discussions, themes were separated into two key topic areas based on the RQs ('evidence of shared identity' and 'factors impacting multiagency working'). The research team met on a fortnightly basis throughout the study.

| RESULTS
The results are presented in relation to the two key topic areas derived from the RQs: (i) 'evidence of shared identity'(RQ1), and (ii) 'factors impacting multiagency working' (RQs 2 and 3; see Table 5; Figure 2).
Themes are presented alongside representative extracts from the interviews. Responders' unique participant number (1-17), their organization (e.g., Police, FRS or Ambulance) and their region (e.g., South) are presented alongside extracts. Additional extracts can be found in Table 5.

| Evidence of shared identity
This topic area relates to the extent to which there was evidence of a shared identity in the multiagency groups. There are two themes

| Vertical intergroup relations
In contrast to the use of collective language at the local level, when responders were discussing their relationship with national level, responders tended to use 'us-vs-them' language, highlighting the disconnect between the two levels: They are doing stuff and we are doing stuff. (P15,

Police, South East)
This was prevalent when responders were talking about communication between national and local level: The big unknown locally, which perhaps they knew more about nationally, was the degree to which lockdown measures was going to be put in place […] we need this information early on. There is a sense that the information exists in Central Government but it's not being shared. (P10, FRS, South East) Furthermore, responders discussed that the disconnect between the two levels was exacerbated by most communication from the national to local level taking place through media and television announcements: The big thing with this one is we all find out what is going to happen next when they stand on the TV and tell us what is going to happen next. We are finding out at the same time as everyone else, then having to respond to this as a strategic and tactical body.

(P4, Police, East)
Discussing what impact this communication had on their ability to respond, one responder said they 'can't contingency plan' when they learn about stuff at the same time as the public: The cat is out of the bag before we have even had a chance to look at it or think about the implications. London, who in the early months of the pandemic seemed to be worse affected than other areas of the country. In addition, one responder (P17, Ambulance) in Scotland discussed sharing lessons internationally, which came about due to the strong international links they have.
As well as providing practical support, this cross-area connection also provided emotional support by 'providing the opportunity to vent and also assurance' (P16, Police, South East). This was also echoed in Scotland where one responder said they recognized that several lives had been lost and that this caused an emotional strain for responders:

| Leadership
This theme refers to the way that the leaders, or chairs, of the multiagency groups, were able to influence group work. This theme is separated into two subthemes: 'understanding the roles of partners' and 'maintaining a common picture of the response'.
Understanding the roles of partners: Several responders said that the biggest difference between the COVID-19 response compared to other incident responses is that it is a health-led initiative and they Maintaining a common picture of the response: In later interviews, some responders said that different organizations developed a different understanding of where they were at in the response and that this reduced the shared sense of common fate. One responder who initially talked about the unity of the group said that later in the response the group cohesiveness that was originally formed started to weaken because there was no longer a clear common purpose for why they were convening: It takes an external threat for everyone to come together to work for the greater good and taking one for the team […] but as soon as that external threat slightly dissipates, even if it is just that we are over the In response to the changing situation, one responder said that their SCG introduced a new phase called 'stabilization' which occurred after the initial response phase, but before the recovery phase. Within this phase, the SCG members were not meeting regularly as they had done in the initial response phase, but partners were still working together and ready to meet again if or when it was necessary. This was so that partners were aware they still had access to the resources and support the SCG could provide: It is well documented within the social identity literature (Drury et al., 2009;Haslam et al., 2009), and recently in the MTS literature (Cujipers et al., 2016;Mell et al., 2020), that individuals identifying with members of their group can help group working and can foster trust in other group members (Turner et al., 1987 Research shows that a sense of common fate between individuals can facilitate a shared identity between members (e.g., Drury, 2018). Subsequently, this shared identity can encourage helpful and empathetic behaviour between group members (e.g., Levine et al., 2005), enhance people's trust with group members (Cruwys et al., 2020) and increase their willingness to cooperate in working towards group goals (Haslam, 2004). Taken in the context of the current research, the shared threat of COVID-19 is likely to have contributed to the development of a sense of common fate among responders (evidenced through the use of collective languages, such as referring to the virus as a 'common enemy'). Thus, this sense of common fate is likely to have facilitated a sense of shared identity and subsequently increased their ability to work together collaboratively on the response.

| Leadership
An early challenge discussed by responders in initial interviews was the wide range of partners involved in the response. This included partners who would not typically be involved in incident response, and with whom pre-existing relationships were not present. Yet, some responders discussed how the Chair of their meetings went over roles and responsibilities at the beginning of the response, or when new partners joined, and how this facilitated their ability to work interdependently with, as opposed to independently, each other.
Furthermore, in later interviews when the initial wave of COVID-19 came to an end, some responders said that the initial sense of shared purpose that was present at the beginning of the response seemed to have waned. As such, some responders said their chair spent time going over where they were at with the response and outlined any outstanding issues to help maintain a common picture of the response amongst responders. Thus, according to some responders', their chair attempted to strategically maintain a shared awareness of the situation in this way and helped facilitate group cohesiveness by ensuring common goals were communicated to all.
According to Zehnder et al. (2017), effective leadership can help organizations foster a sense of shared identity among members, in turn, facilitating collaboration between group members (Ellemers et al., 2004) and making the group more likely to succeed in their goals (Carton et al., 2014). Recently, Fladerer, Haslam et al. (2021) showed that leaders were able to reinforce a sense of shared identity amongst group members by using collective language such as 'we' as opposed to 'I'. In turn, this reinforced sense of shared identity within the group was subsequently associated with improved organizational performance, emphasizing the importance of effective leadership. This is also in line with SIMOC which emphasizes the importance of group leaders in helping employees adjust to organizational change by helping to create a new, positive and meaningful identity (Mühlemann et al., 2022).
Further, in the context of emergency response, recent research has shown that individual characteristics of the Chair of SCG groups can influence decision-making processes within the group (e.g., Waring et al., 2020;Wilkinson et al., 2019). For example, in video footage analysis of groups responding to either a simulated major incident or large-scale exercise, Wilkinson et al. (2019) found between-group differences in the way decision-making activities were carried out. The authors suggested a potential reason for these between-group differences could be due to differences in the composition and characteristics of the group, or the disposition of the Chair.

| Strengths and limitations
One limitation of the research presented is that only responders from the blue-light services were included but the COVID-19 response involved responders from several different organizations. Because of this, it is difficult to discern whether the challenges discussed by responders were common across responders from other organizations involved in the response. The varying availability of responders may have also biased the results to those who took part in the most interviews. Furthermore, the longitudinal data collection method used in the present study is useful for allowing us to understand how aspects of the response, as well as a shared identity within the response groups, changed over time. Thereby, this provides valuable insight into how these processes develop and change, why this might happen, and what effect this subsequently has on multiagency working. However, a key limitation of this methodology is that due to differences in availability for interviews in the ongoing pandemic response, responders took part in an unequal number of interviews.
Because of this, changes over time that are captured in the longitudinal data set are likely to over-represent those who took part in the most interviews. (2022) similarly pointed to the importance of leadership in the locallevel response, as well as the challenges presented by the intergroup relationships between the local and national levels.
Of course, it is possible that there are factors other than social identity processes that may have impacted multiagency working in the COVID-19 response. For example, responders from the South East said they introduced a period of stabilization in between the usual 'Response' and 'Recovery' phase-an interim control stage to mitigate the risk of secondary impacts occurring, as well as allowing multiagency coordination groups to retain their overall focus on reducing the risk of the current threat (Deeming & Burgess, 2017;cf. Deeming, 2020). Recent research looking at the multiagency response to a simulated terrorist incident also found benefits of a three-phased approach (Brown et al., 2021). Brown et al. (2021) suggest that an additional phase between response and recovery can increase opportunities for collaborative working across agencies and reduce demands on a single team. As such, it should not be ignored that factors other than social identity processes can also facilitate effective multiagency working. It is also important to acknowledge that the current study was focused on the strategic and tactical response to COVID-19 which has presented unique challenges for emergency responders in terms of the scale and complexity of the DAVIDSON ET AL.
| 15 response required. However, because of this, it is unclear whether the findings could generalize to other multiagency responses, and it would be beneficial for future research to examine social identity processes in relation to other types of incidents to allow recommendations to be as useful and transferrable as possible.
Finally, while the present study provides useful and valuable insight into how shared identity processes might operate in multiagency response teams, the interview questions did not engage specifically with social identity processes. So, while a non-directive interview protocol was chosen to allow the interviewees to speak directly about things that were most important to them and to allow discussions of relevant social identity processes to occur spontaneously, important aspects relating specifically to social identity may have been missed following this approach. Furthermore, this study does not provide objective evidence that shared identity is associated with improved interoperability. As such, future research would benefit from exploring this issue further using additional data collection methods, including observations of performance and measures of social identification.

| CONCLUSION
The interviews conducted with strategic and tactical responders involved in the COVID-19 response provide evidence of shared identity between responders at the local level. This identity was created and initially made salient by responders sharing pre-existing relationships with each other, which in turn facilitated the way that they were able to work together early in the response. Furthermore, a sense of shared common fate between responders at the local level helped make their shared identity salient early in the response.
However, when pre-existing relationships were not present, or when the initial threat of COVID-19 began to reduce, Chairs of the multiagency groups played an important role in helping to create or maintain a shared identity-for example, by highlighting the roles and responsibilities of partners or emphasizing the shared goals of the response. On the other hand, however, there was limited evidence of a shared identity at the intergroup level between national and local teams, as evidenced by a strong use of 'us vs. them' language on the part of local responders. While in some ways this challenged the local-level response to COVID-19, it also helped make salient their shared identity at a local level. Relationships across areas helped to make responders' shared identity more inclusive and facilitated the local-level response while also providing an outlet for responders at the local level to help them overcome the challenging relationship at the national level.

| PRACTITIONER POINTS
• Relationships between responders from different organizations should be nurtured to ensure that a shared identity is maintained between responders to facilitate the ease at which they are able to come together for future incident responses. For example, organizations should prioritize multiagency training to allow for relationships between responders to develop in advance of a real incident.
• When responders share difficult or challenging experiences with each other, this can help them feel connected to each other, regardless of their organization. During a joint response, responders should be encouraged to use collective terminology, such as 'we' and 'us' to facilitate this. Furthermore, multiagency debriefs should be encouraged as this provides a valuable opportunity for responders to meet and discuss their shared experiences with each other.
• Leadership is important in facilitating a shared identity and chairs of the multiagency groups can help strategically embed a shared identity if relationships are not already present or if there is not a strong sense of common fate between responders.
Chairs can achieve this through specific actions such as making the roles and responsibilities of partners clear and emphasizing shared goals.
• During a nationwide response, strategic and tactical responders at the local level should be encouraged to talk to their neighbouring areas about the response. This can help us to to create a more inclusive sense of shared identity between responders, as well as provide a useful mechanism for sharing best practices to an ongoing response.